WASHINGTON — SpaceX plans to resume Falcon 9 launches on Jan. 8 after completing the investigation into the pad explosion that destroyed another Falcon 9 four months ago.

In a statement posted on the SpaceX website Jan. 2, the company said the explosion was caused by the failure of one of three helium tanks, known as composite overwrapped pressure vessels (COPVs), inside the liquid oxygen tank in the rocket’s second stage. The company had previously indicated that a COPV failure was a leading cause of the accident.

Each COPV is made of an aluminum liner surrounded by a carbon composite overwrap. Other COPVs recovered from the Falcon 9 showed buckling of their liners, although what caused the buckling isn’t stated.

SpaceX said that the buckling, in and of itself, did not cause the tanks to fail. Instead, the company believes the buckles created voids between the liner and composite overwrap where liquid oxygen could pool. “When pressurized, oxygen pooled in this buckle can become trapped; in turn, breaking fibers or friction can ignite the oxygen in the overwrap, causing the COPV to fail,” the company said. The temperature of the helium in the COPV is also cold enough to freeze some of the oxygen, exacerbating the problem.

In its statement, SpaceX said that investigators did not find a single, most likely cause of the failure, but all the potential causes were similar. “The investigation team identified several credible causes for the COPV failure, all of which involve accumulation of super chilled [liquid oxygen] or [solid oxygen] in buckles under the overwrap,” the company stated.

SpaceX’s return-to-flight plans call for changes in procedures for fueling the rocket rather than design changes to the COPVs. According to the company, it will use warmer helium in the COPVs and also change the process for loading helium into those tanks “to a prior flight proven configuration based on operations used in over 700 successful COPV loads.”

The company didn’t state what effect these changes would have on launch preparations or vehicle performance. The current version of the Falcon 9 uses so-called “super-cooled” propellants, where liquid oxygen is chilled to near the freezing point to increase its density and improve the vehicle’s performance. Those propellants are loaded into the Falcon 9 shortly before launch.

Those procedural changes are intended only to be short-term solutions. “In the long term, SpaceX will implement design changes to the COPVs to prevent buckles altogether, which will allow for faster loading operations,” the company stated, but did not give a schedule for making those design changes.

The short-term fixes, though, should allow the Falcon 9 to resume launches that were put on hold after the Sept. 1 pad explosion. That includes the first of seven launches of Iridium Next satellites, which is now scheduled for no earlier than Jan. 8 from Vandenberg Air Force Base in California.

“Iridium is pleased with SpaceX’s announcement on the results of the Sept. 1 anomaly as identified by their accident investigation team, and their plans to target a return to flight on Jan. 8 with the first Iridium Next launch,” Iridium said in a Jan. 2 statement.

That schedule is pending the issuance of a launch license from the U.S. Federal Aviation Administration. The FAA has not granted that license yet, but sources say the FAA has received and is reviewing SpaceX’s report on the pad accident. In its statement, SpaceX noted that the FAA “provided oversight and coordination for the investigation” as part of the investigation team.

Should SpaceX successfully return to flight with the Iridium mission, its next launch is expected to be of the EchoStar-23 communications satellite later in January. That launch will be the first SpaceX mission from Launch Complex 39A at NASA’s Kennedy Space Center in Florida, a former space shuttle pad that SpaceX is leasing primarily for Falcon 9 launches of its Crew Dragon spacecraft and launches of its Falcon Heavy rocket. SpaceX will be using the pad for other Falcon 9 launches because of damage sustained at Space Launch Complex 40 in the September pad explosion.

Quelle: SN

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SpaceX targets Sunday return to flight from California

SpaceX is targeting a Sunday, Jan. 8, return to flight of its Falcon 9 rocket from California, where the company will adjust fueling procedures believed responsible for a Sept. 1 explosion that destroyed a rocket and satellite on their Cape Canaveral launch pad.

Investigators found buckles had formed in the aluminum lining of helium tanks that are about as large as a person.

When the system was pressurized, the buckles trapped pools of liquid or solid oxygen between the linings and an outer layer of carbon wrap covering them. That build-up of oxygen likely created friction or caused carbon fibers to break, SpaceX said, which ignited the oxygen in the rocket’s upper stage during a countdown rehearsal at Cape Canaveral Air Force Station’s Launch Complex 40.

The Falcon 9 and Spacecom’s $200 million Amos-6 commercial communications satellite, which Facebook had hoped to use to extend Internet access in Africa, were lost, and the launch pad was severely damaged.

Schedule of upcoming Florida rocket launches

In an update posted online Monday morning, SpaceX, led by Elon Musk, said the helium tanks will be redesigned, but did not specify when that longer-term change would be implemented.

To prevent buckling in the short-term, the company said it would revert to “a prior flight proven configuration” for loading helium, including loading the gas at a warmer temperature. Those procedures have worked safely more than 700 times, SpaceX said, but take more time.

The planned Jan. 8 launch from Vandenberg Air Force Base will carry the first 10 of at least 70 communications satellites that SpaceX is contracted to launch for Iridium Communications.

As it did through much of the first half of last year, SpaceX plans to try to land the Falcon 9’s first stage on a modified barge in the ocean, continuing efforts to recover and re-launch Falcon boosters.

Before Sunday, SpaceX plans to fuel the Falcon 9 for a practice countdown like the one performed on Sept. 1, intended to end with a brief firing of the rocket's nine Merlin main engines. This time, no payload will be on top.

Recap: 2016 rocket launches from the Space Coast

If the return to flight succeeds, a Falcon 9 could try to launch an unmanned Dragon cargo ship to the International Space Station from Kennedy Space Center before the end of the month.

The Sept. 1 explosion was the second time in 14 months that a Falcon 9 suffered a catastrophic failure. In June 2015, another breach in the upper-stage liquid oxygen tank doomed a Dragon mission to the ISS about two minutes into flight. SpaceX said that problem, attributed to a failed strut, was unrelated to the Sept. 1 explosion.

SpaceX led the recent investigation with oversight from the Federal Aviation Administration, which licenses commercial rocket launches. Other partners included NASA, the Air Force, the National Transportation Safety Board and several unidentified “industry experts.”

“SpaceX greatly appreciates the support of our customers and partners throughout this process, and we look forward to fulfilling our manifest in 2017 and beyond,” the company said in a statement.

Drawing from more than 3,000 channels of data from video and telemetry, the investigation focused on an instant — less than a tenth of a second — from the first sign of trouble to the rocket’s destruction.

For weeks after the accident, Musk did not rule out the possibility that someone might have fired a shot at the rocket.

NASA has been performing its own, independent investigation and has not yet released any findings.

The space agency relies upon SpaceX to deliver cargo to and from the space station, and also hopes to see the company launch astronauts to the outpost in early 2018.

SpaceX's late fueling of the Falcon 9 during the final half-hour of countdowns, when a crew would be sitting atop the rocket, has been a source of concern to NASA and some of its independent safety advisers.

The first ten IridiumNEXT satellites are stacked and encapsulated in the Falcon 9 fairing for a Jan. 8 launch attempt from Vandenberg AFB, CA. Photo Credit: Iridium

SpaceX is aiming to return their workhorse Falcon-9 rocket to flight next Sunday with a fleet of 10 Iridium NEXT satellites. The mission, currently scheduled to lift-off on Jan. 8 at 10:28 a.m. Pacific Time from Space Launch Complex 4E at Vandenberg Air Force Base, Calif., will mark SpaceX’s 30th Falcon-9 and the first launch for SpaceX since a Sept. 1 explosion took out their rocket, Cape Canaveral launch complex, and their customer’s AMOS-6 satellite.

The 10 satellites flying next weekend represent the first set of 70 total that Iridium is launching with SpaceX to replace their current constellation; all of which are contracted to fly on seven Falcon-9 launches over the next 18 months (prior to the AMOS-6 accident, Iridium wanted all their launches flown by the end of 2017).

A landing attempt of the Falcon-9 booster will occur far offshore minutes after launch, using the company’s autonomous “Just Read The Instructions” drone ship as a landing pad.

In the time since the Sep. 1 explosion, the accident investigation has focused heavily on a breach in the cryogenic helium system of the rocket’s second stage liquid oxygen tank, with special attention narrowed to one of the three composite over wrapped pressure vessels (COPVs) inside the LOX tank.

Having worked with numerous agencies, including NASA, the FAA, U.S. Air Force and NTSB, the Hawthorne, Calif.-based company today released final results of the investigation, as well as outlined some of the actions they intend to take moving forward to prevent another AMOS-6 incident from happening again.

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Over the past four months, officials at the Federal Aviation Administration (FAA), the U.S. Air Force (USAF), the National Aeronautics and Space Administration (NASA), the National Transportation Safety Board (NTSB), along with several industry experts, have collaborated with SpaceX on a rigorous investigation to determine the cause of the anomaly that occurred September 1 at Space Launch Complex 40 (SLC-40) at Cape Canaveral Air Force Station in Florida. This investigation team was established according to SpaceX’s accident investigation plan as approved by the FAA. As the primary federal licensing body, the FAA provided oversight and coordination for the investigation.

Investigators scoured more than 3,000 channels of video and telemetry data covering a very brief timeline of events – there were just 93 milliseconds from the first sign of anomalous data to the loss of the second stage, followed by loss of the vehicle. Because the failure occurred on the ground, investigators were also able to review umbilical data, ground-based video, and physical debris. To validate investigation analysis and findings, SpaceX conducted a wide range of tests at its facilities in Hawthorne, California and McGregor, Texas.

The accident investigation team worked systematically through an extensive fault tree analysis and concluded that one of the three composite overwrapped pressure vessels (COPVs) inside the second stage liquid oxygen (LOX) tank failed. Specifically, the investigation team concluded the failure was likely due to the accumulation of oxygen between the COPV liner and overwrap in a void or a buckle in the liner, leading to ignition and the subsequent failure of the COPV.

Each stage of Falcon 9 uses COPVs to store cold helium which is used to maintain tank pressure, and each COPV consists of an aluminum inner liner with a carbon overwrap. The recovered COPVs showed buckles in their liners. Although buckles were not shown to burst a COPV on their own, investigators concluded that super chilled LOX can pool in these buckles under the overwrap. When pressurized, oxygen pooled in this buckle can become trapped; in turn, breaking fibers or friction can ignite the oxygen in the overwrap, causing the COPV to fail. In addition, investigators determined that the loading temperature of the helium was cold enough to create solid oxygen (SOX), which exacerbates the possibility of oxygen becoming trapped as well as the likelihood of friction ignition.

Quelle: AS

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Update: 7.01.2017

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Foul Weather Pushes SpaceX’s Next Launch to Monday

SPACEX’S ARMY OF hopers and believers have been holding their breath in anticipation of its next launch. They’ll be blue in the face just a bit longer: The liftoff, which had been planned for this Sunday, January 8, has been pushed back a day due to foul weather.

The announcement, until now a rumor circulated in local Central California media, was made official today on the website of Iridium, SpaceX’s customer for the launch. This is SpaceX’s first launch since a Falcon 9 bearing a $200 million satellite blew up on September 1, 2016. This mission isn’t a redo of the Spacecom satellite that blew up, but the first in a series of seven for Iridium will launch a total of 70 miniature telecommunications satellites.

The launch, now scheduled for January 9, 10:22am PST, has been delayed because of foul weather. SpaceX’s west coast launch pad is located at Vandenberg Air Force base, in the mountainous shore north of the company’s Hawthorne, CA headquarters. Starting Saturday evening, Vandenberg, along with the rest of California, will get drenched by an invisible, incredibly moist tendril of air extending from the tropics. Meteorologists expect the so-called atmospheric river to drop upwards of a foot of rain on low-lying areas. Obviously, not the best conditions to launch a rocket.

Especially a rocket launch that every space junkie on the planet will be watching. Another failure would be very bad for SpaceX, because although the company still has a few years worth of launches on the books, it will have a hard time selling future customers on its safety record with a pair of back-to-back launchpad mishaps. And Musk would be selling his launches against the superior safety records of competitors like United Launch Alliance, Sierra Nevada, and Orbital ATK.

However, none of those other companies are landing their rockets, nor do they have any other clear path towards democratizing access to space. (Yeah, yeah, Blue Origin is landing rockets, but not rockets capable of taking big payloads into high orbits, like the Falcon 9 has done time and again.) Last year, the company landed four of its Cape Canaveral-launched Falcon 9 rockets on a droneship. And another two touched down on dry land. Re-launching Falcon 9s would save SpaceX tens of millions of dollars per launch.

Reusability, along with other pioneering budget-busters like highly compressed propellant, are what SpaceX was banking on in order to fulfill its promise of offering spaceflight to civilians. Elon Musk had been promising the first such re-launch would happen in late 2016. Now … well, let’s just get through Monday.

Or Tuesday, or Wednesday, or whenever California’s skies clear up enough for liftoff.

Reasons for the delay aren’t known, but weather-related postponements typically don’t occur more than 24 hours before liftoff. The team likely is battling other issues that can involve the technical troubles with a rocket, satellites or ground support equipment or even scheduling conflicts with other activities at Vandenberg.

Even if they are tackling technical troubles, the weather looked less than accommodating for a Monday launch attempt, however, as heavy rains are expected with an incoming winter storm.

Rainy conditions are expected for most of the week, with Saturday hinting at one of the best chances for sunshine, according to the National Weather Service.

While many launches have longer windows that offer multiple chances to get off the ground, this mission has just one moment a day so the Iridium satellites can be placed in the proper place in space. The launch moves several minutes early for each day it delays.

Since late Friday, other signs hinted that a Monday attempt appeared shaky. Vandenberg officials did not release information about the upcoming launch as they typically do.

As of Friday morning, Iridium officials were hopeful for a Monday attempt

“Looks like we’re good to go for Monday!” Desch said Friday on Twitter. “Payload/rocket mating underway; we’ll just have to see about the weather. Anti-rain dances, anyone?”

The Falcon will carry the first 10 Iridium NEXT satellites to begin building the second-generation constellation of craft for the space-based phone system.

“The finish line of the marathon is in sight,” said Scott Smith, Iridium chief operating officer. “The satellites are ready. The rocket is ready. Operations is ready. A new era is about to begin!”

“With completion of the static fire test, our first launch has just gotten that much closer,” Desch said.

“The Iridium team has been anxiously awaiting launch day, and we’re now all the more excited to send those first 10 Iridium Next satellites into orbit.”

The license came after the FAA accepted the investigation report on the dramatic Sept. 1 mishap in which a Falcon erupted into a fireball during an on-pad test in Florida.

In what is expected to be a first for the West Coast, SpaceX plans to possibly land the Falcon rocket’s first stage on a barge off the coast, according to the FAA license, which also mentions an ocean landing option.

SpaceX has conducted several flyback missions as part of Florida launches after the Falcon fulfilled the rocket’s primary mission.

Unlike landlines and cell phones, the Iridium system provides coverage over 100 percent of the earth’s surface, including across oceans, airways and polar regions, company representatives said.

The revolutionary system launched a majority of its original satellites plus several spares from Vandenberg aboard Delta II rockets between 1997 and 2002.

The campaign meant jobs for the launch crews plus full hotels and restaurants when support staff and visitors came to watch the blastoffs.

The system is named for the 77th chemical element on the Periodic Table —marking the original number of craft planned for the constellation.

While design changes meant fewer satellites for the constellation, the moniker remained.

Falcon rocket launches from Vandenberg can be viewed from various viewing sites around the Lompoc Valley since the launch pad is visible south of West Ocean Avenue (Highway 246).

Quelle: Noozhawk

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Update: 9.01.2017

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SpaceX’s return to spaceflight pushed back to January 14th

The delay is due to high winds and rain near the launch site

SpaceX’s first rocket launch since August has been pushed back to January 14th, due to rain and heavy winds that are expected near the launch site in California over the next week. Prior to the delay, SpaceX had been aiming to launch on January 9th, after receiving a launch license from the Federal Aviation Administration. On Friday, the FAA announced it had accepted SpaceX’s explanation for what caused one of the company’s Falcon 9 rockets to explode on a Florida launch pad.

“THE FAA ACCEPTED THE INVESTIGATION REPORT ON THE AMOS 6.”

SpaceX has been grounded since the accident, which occurred on the morning of September 1st. The Falcon 9 was being fueled in preparation for a pre-flight test, when it exploded in a fireball, destroying both the rocket and the Amos 6 satellite it was supposed to carry into space. The company has spent the past four months trying to figure out what caused the incident, coming to the conclusion that the failure began with helium pressure vessels located in the rocket’s upper oxygen tank. Liquid oxygen propellent is thought to have ignited after getting trapped in materials surrounding the helium vessels.

“The FAA accepted the investigation report on the Amos 6 mishap and has closed the investigation,” the FAA said in an email statement to The Verge on Friday. “SpaceX applied for a license to launch the Iridium NEXT satellites from Vandenberg Air Force Base. The FAA has granted a license for that purpose.”

Now, SpaceX is looking to return to flight by launching 10 satellites for communications company Iridium, as part of the Iridium NEXT mission. The launch is slated to take place from Vandenberg Air Force Base in California on January 14th, at 12:54PM ET. Following the flight, SpaceX will try to land the majority of its rocket on one of its drone ships in the Pacific Ocean.

A major NASA safety advisory group urged the agency to scrutinize SpaceX’s rocket fueling process ahead of future launches of astronauts to the International Space Station.

The Aerospace Safety Advisory Panel brought up concerns about the Hawthorne space company’s unconventional fueling operations in its 2016 annual report, released Wednesday.

Described in the report as the “load and go” approach, SpaceX plans to have the astronauts board the Crew Dragon spacecraft before final fueling of the rocket.

SpaceX uses super-chilled liquid oxygen to maximize the amount that can fit in the tank and increase power at liftoff to hoist heavy loads. But the extremely cold temperature means that the liquid oxygen needs to be loaded right before launch.

In the report, the panel said it was concerned that potential risks associated with loading propellants into the rocket with astronauts onboard were not “adequately understood.”

The panel was created in 1968 by Congress to advise and give recommendations on safety issues to the NASA administrator. The group is the primary safety advisory panel for the commercial crew program.

SpaceX said Thursday in a statement that its fueling and launch process was “reliable” and “minimizes” the time and number of people exposed to “the hazards of launching a rocket.”

SpaceX has a contract from NASA to build and launch a crew capsule to transport astronauts to the space station. NASA has said the first uncrewed flight test of SpaceX’s capsule is set for November, and the first flight with humans aboard is scheduled for November 2018.

The company said that its Crew Dragon launch abort system will be enabled after astronauts board the spacecraft and fueling begins. In case of an emergency, the abort system uses several rockets built into the walls of the spacecraft to push the astronauts away from the rocket; the capsule floats back to Earth on parachutes.

Though the panel’s concerns are specific to astronaut launches, SpaceX also currently uses the same fueling routine for satellite launches.

The report also mentioned the company’s September launch pad explosion in Florida, which destroyed a Falcon 9 rocket and commercial communications satellite perched on top. SpaceX plans to return to flight Saturday with a launch of 10 satellites for Iridium Communications Inc.

The panel said that NASA will also review the September incident, and it urged the agency to focus not only on the cause but also on the “load and go” fueling process.

Despite rounds of testing, issues can often pop up once procedures are actually used in a real-time environment, the report states.

“We strongly encourage NASA top management to scrutinize this issue and ensure that any decision to accept additional risk or novel risk controls with large uncertainties is justified by the value that will be gained.”

SpaceX said this month that the explosion was caused by a failed composite overwrapped pressure vessel, which carries cold helium, in the rocket’s second-stage liquid oxygen tank. To fix the problem, the company said it will change the configuration of the vessels so warmer helium can be loaded, and change helium loading operations to the way they had been in the past.

In its statement, SpaceX said it has performed a “detailed” safety analysis with NASA over the last year and a half of all potential hazards in its fueling process. The company said safeguards against these hazards have been identified and will be verified before it receives certification to launch astronauts.